I have heard of this also, mainly because some companies do not purify their water, some bacteria can still exist in the bottles. If you fear that this could happen, there are a few simple steps to rectify this problem.
1) use what you store, and rotate stock.
2) with the clear plastic bottles, put them out in the sunlight for an hour, and the UV rays will kill off most bacteria.
3) research the company that you buy the water from.

Regulations say all food products must have an expiry date. Someone decided on 2 years for water. Not an expiry date either, a "best before".

Doesn't hurt to rotate them out. I always have one flat of 36 being used for my work lunch bag, jogging etc and at least 2 for just in case. Since I'm only prepping for myself it's plenty.
But after the recent flood I think I might start storing more for giving away. It's clear that in a SHTF scenario when the laymans are clearing store shelves in a panic, first responders will be needing supplies. It would be nice to show up with a truck full of water to give away

DaScribbler,

water bottles have an expiration date based on two factors;
1. the purity of the water and additives that they put in

2. the main one, the quality of the water bottles and level of plastic.
a. look to the bottom the ones with the Recycle symbol and the letter 3 - are the highest grade for general consumption.
b. if it has a number 1 or none on the bottom, they are designed to break down faster in the landfill.

There are higher levels of plastic bottles that are speciality bottles for fuels or for purity for scientific reasons. Pop bottles from mane suppliers say Coke/Ginger Ale, normally are a # 2 they are food safe and last considerably longer than the # 1 bottles.
# 3 are for food storage and purity, break down very slowly and contain no BPAs same as the # 2s

if you leave the bottles right on concrete, or freeze the bottles they break down much faster and in fact they start to break down even in the stores.

Thank You for your replies 🙂

I'm not a big Bottled Water drinker, but keep an excess of 36 Gallons of bottled water on hand for emergencies.

I've checked the bottles and all are #1 Bottles and 27 gallons are near or past the stamped expiry date. I'm moving these expired bottles to my cold storage room as there is little to no chance of my going through them anytime soon.

So, as these bottles apparently break down faster then others, my tentative plan would be to keep them and put the water through a Brita filter or Aqua Pail before consuming them in a SHTF situation. This could be tomorrow or another few years down the road.

As most on this board are far more knowledgeable them myself, is it safe to go this route or would I be best to simply dispose of them and restock with fresh supply?

Edited to Add

#1 (PET or PETE) plastic is the kind used for bottled water bottles, which are generally regarded as safe. They have been shown to leach antimony into the water in a couple of studies, but at levels considered safe by the EPA. The scare about their leaching DEHA if reused, which you may have come across, turns out to be an urban legend. If there is any risk from reuse, it probably comes from bacterial contamination. (The bottles' narrow necks make them hard to clean.)

From: http://www.nrdc.org/thisgreenlife/0902.asp

I would personally use them

keep and use,
depending on how long they have expired and how much plastic is floating around, you might want to rig up a sand filer or even some mesh to catch the plastic particle bits.
cheesecloth or some other cloth that is very fine should do.

keep and use,
depending on how long they have expired and how much plastic is floating around, you might want to rig up a sand filer or even some mesh to catch the plastic particle bits.
cheesecloth or some other cloth that is very fine should do.

Coffee Filters?

FWIW

http://www.chow.com/food-news/53959/does-bottled-water-ever-go-bad/

Lot's of info on the web. General consensus is plastic is bad. How bad is up to your risk appetite. Dying from dehydration is worse.

A little tidbit from http://www.bottledwater.org/ These guys are the group that reps the water bottlers.

Consumers also ask about expiration dates printed on some bottles and whether bottled water has a limited shelf life.

In addition, only one state (New Jersey) has ever required expiration dating for bottled water. However, the New Jersey state legislature repealed the 2-year expiration date law several years ago, noting that there was no scientific evidence to support such a requirement. Some companies place date-based lot codes on bottled water containers, which are typically used to assist in managing stock rotation at distribution and retails points.

Bottled water is an excellent choice for emergency water storage and, of course, daily refreshment. FDA Good Manufacturing Practices mandate that bottled water be produced in a sanitary environment and bottled in sanitary, safety-sealed containers. These and other extensive FDA, state and industry standards help ensure that bottled water delivers consistent safety, quality and good taste to consumers.
- See more at: http://www.bottledwater.org/education/bottled-water-storage#sthash.2wmh8gH0.dpuf

Don't take it a gospel. Do your own research.

keep and use,
depending on how long they have expired and how much plastic is floating around, you might want to rig up a sand filer or even some mesh to catch the plastic particle bits.
cheesecloth or some other cloth that is very fine should do.

Coffee Filters?

Coffee filters are an excellent primary particulate filter.

keep and use,
depending on how long they have expired and how much plastic is floating around, you might want to rig up a sand filer or even some mesh to catch the plastic particle bits.
cheesecloth or some other cloth that is very fine should do.

Coffee Filters?

I was looking at some very fine wire/plastic mesh coffee filters the other day, that would definetly work!

Wilde - are those the "reusable" coffee filters that don't need a paper filter?? that would be a handy extra and inexpensive idea!

Anita, yes in the Grocery store as low as only $6, slight modification and it could work out just fine I think.

I was looking for them recently as someone offered me coffee and pulled that out, put in fresh grinds and voila.. impressive coffee, yummy! Up till then I had not even given those filters a second look really.

Want to see how fast those little water bottles break down, freeze one, let it thaw out, then bank it on a countertop,
It looks like a snowglobe then! All them little plastic bits floating around, so yummy and healthy!!